Machinery of the general character to which we refer is illustrated and described in the following patents:
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Beginning with the machine described,in the present assignee's prior U.S. Pat. No. 3,661,333, it became possible to reduce entire trees with attached limbs and branches to chips in forest locations. In these tree harvesting operations the machines were moved to various locations in tree plantations or the forest, and chip collecting trucks were loaded at these sites to then haul the chips to the processing plants. Particularly, these forestry operations involved thinning and clean-up of the area surrounding the sites by removing those trees which were ready for harvesting, or were interfering with the growth of trees it was desired to leave to continue their growth, and removing other trees which otherwise would have been left to rot on the forest floor and wasted.
Machines of the prior art were designed to be capable of handling trees with crooked trunks and limbs and bushy, hard-to-handle hardwood trees of a very "limby" nature. The chips from the trees processed had a wide variety of uses and, during the recent energy "crunch", the chips were burned in some localities to provide a valuable energy resource.
The paper industry requires chips of high quality which are within carefully selected size and shape specifications. Chippers which provide chips for the paper industry are arranged at an acute angle of 371/2.degree. to the longitudinal pathway of feed, to effect the chipping cut and achieve the chip length desired by the paper manufacturers for their chips.
One of the prime objects of the present invention is to provide a portable chipper feed works which operates with a low power, high feeding torque and feeds the tree butt-first to the anvil along a pathway which ensures that the tree is continually presented to the rotating, knife supporting disc at an angle such that the 371/2.degree. relationship is maintained, and chips are cut from the tree at that angle.
Another object of the invention is to provide a feed works which provides for minimum contact of the whole tree with the feed works while still functioning to positively feed the tree at the required angle. With the present design it is contemplated that a lower horsepower, much less expensive engine can be used than is possible with machines of the type disclosed in U.S. Pat. No. 3,661,333.
A further object of the invention is to provide a portable chipper with a feed works which permits the use of a loader which loads the tree on the fly, directly to feed wheels which are located directly adjacent the chipper housing mouth.
Another object of the invention is to provide a machine which eliminates the need for a chain saw operator to saw certain limbs from the tree before processing the tree, the present chipper having a construction such that a heavy limb on the tree can be fed to the chipper mouth in a particular orientation on the "open" side, in which it can be chipped off.
Another object of the invention is to provide a portable chipper with feed works which adapts to the changing diameter of the trunk during the tree chipping operation such that the butt end of the tree is always being presented to the chipper disc at the proper angle, and uniform chips of the required size and shape are produced by the body of the tree as well as by the chipping of the butt end.
Another object of the invention is to provide a bridge between the feed wheels and mouth of the chipper disc which is so shaped and located as to avoid as much frictional contact with the trees being processed as possible, the feed wheels of the assembly operating in conjunction with the bridging chute surface to accomplish this purpose.
Still another object of the invention is to provide a feed works for a portable chipper, wherein a partial chute can be used, which has a partly conical surface and presents as little obstacle to the passage of the tree into the chipper housing opening as possible, this permitting the feed system to operate with as little power as possible because sliding friction is avoided for the most part and the tree is processed instead with principally a rolling frictional contact with the feed works components.
Still another object of the invention is to provide a readily operable plow device for moving collected debris, such as twigs, leaves and small brush from the vicinity of the feed works.
Still a further object of the invention is to provide an economically manufactured and maintained chipper and feed works assembly which can be operated most efficiently and reliably by foresters who are desirous of producing uniformly high quality chips.